/**
 * Copyright 2009 Emory University
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated  * documentation files (the 
 * "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions: The above copyright notice and this permission
 * notice shall be included in all copies or substantial portions of the
 * Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
 * EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
package com.markgrand.structuredSql;

import java.util.ArrayList;
import java.util.List;

/**
 * Model an order-by constraint for use in an SQL statement.
 * 
 * @author Mark Grand
 */
class OrderByConstraint protected (val orderByColumns: Seq[OrderByColumn]) extends SQLAppender {
  if (orderByColumns.length==0) {
    throw new IllegalArgumentException("From list must contain at least one from item.")
  }

  /**
   * Append an SQL representation of this object to the given StringBuilder object.
   */
  def append(builder:StringBuilder) {
      builder.append("ORDER BY ");
      orderByColumns.addString(builder, ",")
  }
}

object OrderByConstraint {
  def apply(orderByColumns: OrderByColumn*)= new OrderByConstraint(orderByColumns)
  
  def apply(orderByColumn:String, direction : OrderByDirection.Value):OrderByConstraint = apply(OrderByColumn(TableColumnIdentifier(orderByColumn), direction))
  
  def apply(orderByColumn:String):OrderByConstraint = apply(orderByColumn, OrderByDirection.ASCENDING)
}
